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Residential Lighting Loads

The general lighting load for a residential dwelling unit is based on 3 va per square foot of space. To determine the area, use outside measurements. Then multiply the square feet times 3 va. The result will be the general lighting load.

To determine the minimum number of 15 amp circuits for this load, divide by 120, then divided by 15. The result will be the minimum number of circuits needed for this load. Round up to the next whole number if there is a remainder.

The same calculation is made if 20 amp circuits are to be installed. So it is the total square feet times 3 divided by 120 then divided by 20. If there is a remainder, round up.

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